In ethanol production biomass, such as sugar cane, energy cane and sorghum, is used as raw material. A typical ethanol production process is shown below. Biomass stalks are shredded or cut to reduce the size of the biomass material. Then the biomass stalks are pressed and the resulting stalk juice is filtrated and concentrated by evaporation. The free sugar molecules in the sugar solution, resulting from the filtration, are fermented and the fermented solution is distilled to purify and concentrate the ethanol. Thereafter the ethanol is dehydrated. The ethanol production process is shown in FIG. 5.
The ethanol production process shown in FIG. 5 has several drawbacks. It comprises several steps and is thus complicated. It requires a large amount of water, chemicals and energy and is thus expensive and not environmentally friendly.
As a consequence, in light of the above drawbacks, there is a need of an improved method for producing ethanol and an improved ethanol producing system which are less complicated, less expensive and more environmentally friendly.